For various kinds of applications, it is known to utilize power switch devices. For example in the automotive field, power switch devices may be utilized for switching signals with large value of electric current, e.g., in the range of 1 A or more.
For various reasons, it is desirable to build such power devices as a semiconductor device package with a low pin count. A low pin count may help to achieve good thermal and electrical performance while maintaining low production costs. One way to limit the pin count is to omit a dedicated ground pin and implement the power switch device as a current controlled device. In such current controlled device, switching to an on state, where a load current can pass through the power switch device, is achieved by externally connecting a control input pin of the power switch device to ground. In this state, the control input pin also acts as a ground connection of the power switch device. Switching to an off state, where the load current cannot pass through the power switch device, is achieved by disconnecting the control input pin from ground, which at the same time leaves the power switch device without supply voltage.
However, the above way of using a current controlled implementation without a dedicated ground pin may have the effect that the power switch device might not be able to distinguish between intentional switching to the off state and sudden drops of the supply voltage, for example due to short-circuiting of a load connected to the power switch device. This may limit operability and functionality of the power switch device.
Accordingly there is a need for techniques which allow for efficiently operating a power switch device without requiring excessive amounts of terminals on the power switch device.